The brutalist Alfa Romeo SZ coupe and RZ roadster twins of 1989-93, tagged “Il Mostro,” are generally described as Zagato designs. As is often the case in Italy, though, that’s only partly true. Zagato oversaw the project and handled production, but Robert Opron of Alfa Centro Stile created the initial drawings.

Opron was part of Walter Da Silva’s team and Alfa Romeo’s early use of computer-aided CAD/CAM design is often credited (or blamed) for the result. The origami twins first drew breath as the ES30 concept in February 1987 and the resulting SZ Coupe puzzled the press at the 1989 Geneva Show, only 19 months later. The price matched the contemporary Porsche 911, which suggested limited sales were likely.

The SZ coupe was radical in appearance with a floating greenhouse on top of a red wedge and six diminutive and menacing Carello headlights. The body of methacrylic resin was bonded to the steel chassis (with widely varying gaps) and Alfa Romeo reckoned it could build as many as 10,000 units a year. That never happened, and only 1036 coupes left the factory, all red with a gray roof. The convertible that followed in 1992 missed its modest target of 350 units. Only 274 found buyers.

The SZ shared underpinnings with Alfa Romeo’s 75 sedan, which raced in Group A Touring Car competition. Assembly took place at Zagato’s Terrazano di Rho factory, hence the attribution to the coachbuilder. The engine in the SZ is a 207-bhp version of the 75’s “Busso” 3.0-liter V-6, with improved intake and exhaust manifolds and Bosch Motronic fuel injection. A 24-valve engine didn’t arrive in time, so the SZ got the existing 12-valve engine instead. It fits longitudinally and drives the rear wheels through a 5-speed transaxle. The SZ’s claimed top speed is 143 mph and 0-60 comes in 7 seconds.

Alfa factory test driver Giorgio Pianta, who had prepared Lancia rally cars for Walter Rohrl and Henri Toivenen, improved the Alfa 75 sedan’s platform by trading 75’s front torsion bars for coil springs and wishbones with trailing links, and by adding a de Dion rear axle with Watts linkage. Pianta claimed 1.4g in the corners in dry conditions. Newly-developed Pirelli P Zero tires provided added traction. Another feature was the adjustable ride height. The push of a button could lift the body two inches.

After building 1036 coupes, Alfa followed up with the RZ convertible in 1992. While it was mechanically identical, it shared very few body panels with the hardtop – just the front fenders and trunk lid. The RZ hood eliminated the air ducts and the rear lip was kicked up to cover the wipers. The blunt chin spoiler was raised an inch, easing access to parking lots, and the side skirts were redesigned. The windshield was cut down two inches and side windows curved to match windshield angles. The rear deck received a Zagato-style double hump and the manual top folded underneath it.

Alfa Romeo aimed to sell a modest 350 RZ convertibles, but the Zagato producing the cars went into receivership after delivering just 242 examples. The receivers completed 32 more, at which point the project was abandoned.

Due to the small numbers built, the SZ and RZ are a rare sight, especially in the States. Alfa never officially sold them in the U.S., so spares and service is a challenge. The styling also remains an acquired taste and the performance isn’t exceptional by today’s standards, but these cars are quite collectible in certain crowds. And on looks alone, it is one of the most distinctive cars of the 1990s.